With the coming of the era of third generation mobile communication technology (3G), the extension of the terminal market is accelerated in the worldwide. To attract user groups, operators around the world unremittently pursue the individual service of their own products and software and try to improve the user experience, so that the good user experience is the ultimate goal of the competition. From the user's perspective, on the one hand, the operator considers to restrict the local users not belonging to that operator from freely using their products and software to avoid a series of problems due to the improper operations by such users; on the other hand, the operator also considers that the local users might be developed to visited users, and its own products is needed to be used cooperatively with the visited operator's products.
To prohibit other operators from using the products and software, the traditional terminal product will perform network locking to the terminal device according to the operator's mobile country code (MCC) and mobile network code (MNC), while providing the unlocking service by the terminal management software, in which that unlocking service must be implemented with a Subscriber Identity Module (SIM) card, that is, the terminal device, the terminal management software and the SIM card are three indispensable requirements. Obviously, the traditional unlocking solution cannot meet the requirement that the local user are able to use the product in a visited place, this is because the user's original SIM card does not work normally or the cost is too high in the visited place, and the user in the visited place cannot conveniently resort to the product operator to unlock the device.
Therefore, the traditional solution for unlocking the terminal device must be improved to conveniently meet the requirement that the local user be able to use the products in the visited places, thus attracting user groups and improve the user experience.